1. Field of the Invention
The present invention relates to an electrical device with a waterproof keypad, more particularly to an electrical device with a waterproof keypad using a waterproofing pad body for achieving a waterproof effect.
2. Description of the Related Art
Referring to FIG. 1, a conventional electrical device 1 with a waterproof keypad includes a housing 11, a circuit unit 12 disposed in the housing 11, a waterproof keypad 13 disposed in the housing 11 at a position above the circuit unit 12, and a press member 14 connected to the waterproof keypad 13. The waterproof keypad 13 and the press member 14 are secured with the use of screws. The waterproof keypad 13 includes a rubber pad 131 and a plurality of keys 132 disposed on the rubber pad 131. A waterproofing ring 133 projects from a bottom face of the rubber pad 131. When one of the keys 132 is pressed, a part of the rubber pad 131 deforms and actuates a switch disposed on the circuit unit 12.
When the waterproof keypad 13 is disposed in the housing 11, the waterproofing ring 133 surrounds the perimeter of the circuit unit 12 to achieve a waterproof effect of the waterproof keypad 13. Moreover, a pressure exerted upon the rubber pad 131 by the press member 14 forces the waterproofing ring 13 to abut against the housing 11 so as to avoid water or other liquids from permeating through a gap between the waterproofing ring 133 and the housing 11, thereby avoiding short-circuiting of the circuit unit 12.
However, a disadvantage of conventional structure resides in that, because the rubber pad 131 is made of a resilient material, the rubber pad 131 easily deforms curvedly when subjected to a pressure or other forces. For example, torsion due to a screw causes a part of the rubber pad 131 to twist and deform during screwing. Once the rubber pad 131 deforms, it is not ensured that the press member 14 can evenly abut against the rubber pad 131. As a result, because it is possible that the pressure exerted upon a part of the rubber pad 131 is not sufficient, a gap is likely to form between the waterproofing ring 131 and the housing 11, and water or other liquids can permeate through the gap and cause damage to the circuit unit 12. It has been verified through experiments that the waterproof effect of the conventional structure can meet about the IPX4 standard in the IEC 60529.